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// SPDX-License-Identifier: GPL-2.0-only
/*
* Exynos generic interconnect provider driver
*
* Copyright (c) 2020 Samsung Electronics Co., Ltd.
*
* Authors: Artur Świgoń <a.swigon@samsung.com>
* Sylwester Nawrocki <s.nawrocki@samsung.com>
*/
#include <linux/device.h>
#include <linux/interconnect-provider.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_qos.h>
#include <linux/slab.h>
#define EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO 8
struct exynos_icc_priv {
struct device *dev;
/* One interconnect node per provider */
struct icc_provider provider;
struct icc_node *node;
struct dev_pm_qos_request qos_req;
u32 bus_clk_ratio;
};
static struct icc_node *exynos_icc_get_parent(struct device_node *np)
{
struct of_phandle_args args;
struct icc_node_data *icc_node_data;
struct icc_node *icc_node;
int num, ret;
num = of_count_phandle_with_args(np, "interconnects",
"#interconnect-cells");
if (num < 1)
return NULL; /* parent nodes are optional */
/* Get the interconnect target node */
ret = of_parse_phandle_with_args(np, "interconnects",
"#interconnect-cells", 0, &args);
if (ret < 0)
return ERR_PTR(ret);
icc_node_data = of_icc_get_from_provider(&args);
of_node_put(args.np);
if (IS_ERR(icc_node_data))
return ERR_CAST(icc_node_data);
icc_node = icc_node_data->node;
kfree(icc_node_data);
return icc_node;
}
static int exynos_generic_icc_set(struct icc_node *src, struct icc_node *dst)
{
struct exynos_icc_priv *src_priv = src->data, *dst_priv = dst->data;
s32 src_freq = max(src->avg_bw, src->peak_bw) / src_priv->bus_clk_ratio;
s32 dst_freq = max(dst->avg_bw, dst->peak_bw) / dst_priv->bus_clk_ratio;
int ret;
ret = dev_pm_qos_update_request(&src_priv->qos_req, src_freq);
if (ret < 0) {
dev_err(src_priv->dev, "failed to update PM QoS of %s (src)\n",
src->name);
return ret;
}
ret = dev_pm_qos_update_request(&dst_priv->qos_req, dst_freq);
if (ret < 0) {
dev_err(dst_priv->dev, "failed to update PM QoS of %s (dst)\n",
dst->name);
return ret;
}
return 0;
}
static struct icc_node *exynos_generic_icc_xlate(const struct of_phandle_args *spec,
void *data)
{
struct exynos_icc_priv *priv = data;
if (spec->np != priv->dev->parent->of_node)
return ERR_PTR(-EINVAL);
return priv->node;
}
static void exynos_generic_icc_remove(struct platform_device *pdev)
{
struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
icc_provider_deregister(&priv->provider);
icc_nodes_remove(&priv->provider);
}
static int exynos_generic_icc_probe(struct platform_device *pdev)
{
struct device *bus_dev = pdev->dev.parent;
struct exynos_icc_priv *priv;
struct icc_provider *provider;
struct icc_node *icc_node, *icc_parent_node;
int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = &pdev->dev;
platform_set_drvdata(pdev, priv);
provider = &priv->provider;
provider->set = exynos_generic_icc_set;
provider->aggregate = icc_std_aggregate;
provider->xlate = exynos_generic_icc_xlate;
provider->dev = bus_dev;
provider->inter_set = true;
provider->data = priv;
icc_provider_init(provider);
icc_node = icc_node_create(pdev->id);
if (IS_ERR(icc_node))
return PTR_ERR(icc_node);
priv->node = icc_node;
icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
bus_dev->of_node);
if (of_property_read_u32(bus_dev->of_node, "samsung,data-clock-ratio",
&priv->bus_clk_ratio))
priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO;
icc_node->data = priv;
icc_node_add(icc_node, provider);
/*
* Register a PM QoS request for the parent (devfreq) device.
*/
ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req,
DEV_PM_QOS_MIN_FREQUENCY, 0);
if (ret < 0)
goto err_node_del;
icc_parent_node = exynos_icc_get_parent(bus_dev->of_node);
if (IS_ERR(icc_parent_node)) {
ret = PTR_ERR(icc_parent_node);
goto err_pmqos_del;
}
if (icc_parent_node) {
ret = icc_link_create(icc_node, icc_parent_node->id);
if (ret < 0)
goto err_pmqos_del;
}
ret = icc_provider_register(provider);
if (ret < 0)
goto err_pmqos_del;
return 0;
err_pmqos_del:
dev_pm_qos_remove_request(&priv->qos_req);
err_node_del:
icc_nodes_remove(provider);
return ret;
}
static struct platform_driver exynos_generic_icc_driver = {
.driver = {
.name = "exynos-generic-icc",
.sync_state = icc_sync_state,
},
.probe = exynos_generic_icc_probe,
.remove_new = exynos_generic_icc_remove,
};
module_platform_driver(exynos_generic_icc_driver);
MODULE_DESCRIPTION("Exynos generic interconnect driver");
MODULE_AUTHOR("Artur Świgoń <a.swigon@samsung.com>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:exynos-generic-icc");